Posted Mon Feb 13, 2012, 1:32pm Subject: Gaggia Baby Class Modding - Different than other Gaggia's, but it can be done

Hi all, been reading for some time and thought I'd post. On my lunch break so no pictures yet but I'll update this as I go along. Hopefully it will help others in the future.

Bought a Gaggia Baby Class, slight preference for it's looks over the Classic. Didn't realize it would be different inside. In retrospect I'd have broken even and saved work I bet if I'd just gotten the Classic to begin with. Live and learn. No one seems to talk about modding the Baby Class, it's different, but the same ideas apply.

Again I'll get some pics up, but here's what I've done:

1) Installed an adjustable OPV: I purchased the standard OPV for a Gaggia Classic, and it bolted right up (same boiler, same attachments). new OPV came with an O-ring, which was nice, but I could have easily reused the current one. FYI, The original boiler inlet was just a fitting with no valve inside at all - instead, the over pressure release was a chunk of plastic attached to the pump itself. It is an "11 bar valve assy" by name, so I didn't bother even checking what it put out. It is not adjustable - not much anyways, it is spring loaded diaphragm, but as you unscrew it you are disassembling it as well and that didn't seem like a good idea (new OPV has an internal adjustment with a very long range, and a cover to go on afterwards - much better, and apparently made to be adjusted). So - the new OPV is attached to the boiler, the old OPV is left in place but it's release route now has a pipe plug in it (no need for 2 release points, and it makes plumbing easier to not have extra tubes in the machine).

2) Wrapped copper tubing around the boiler to preheat the water: Similar to what you've seen in pictures with the Classic, however there's a plastic cage over everything to support the steam valve, so you have to wrap a little tighter and be mindful of the size and location of your connections so you can replace the cage afterwards. I guesstimate that I ran 5-6' of tubing. Did it by hand, just being careful to not kink it. Also keep in mind what direction you plan to have the tubing point for your connections as you will need an inch or so of straight tubing (no bends or oval shapes at all) to get your fittings installed (don't curl up all of your tubing and then try to straighten the ends later!). A Dremel came in handy here to get a nice flat cut at each end. I folded up some aluminum foil and wrapped it around the tubing afterwards. I figured it can't hurt contain the heat where I want it. Made sure the foil and the tubing both won't hit any electrical contacts.

3) Added a pressure gauge: Contemplated several mounting options and finally settled on a low one in the base for several reasons. First, a lowr point wouldn't have a problem with air getting trapped in it and messing with the readings, and second it makes the plumbing easier by keeping it in place and not having it come on and off with the cover of the machine itself.

4) Replaced the wand tip with another Gaggia wand. Silvia wand is a much different connection and doesn't transfer over. got this one: Click Here (www.seattlecoffeegear.com) It goes right in place and doesn't have all the holes in it to suck in air. just 1 hole in fact which is easily covered up. They claim it's an improvement, we will see once things are back up and running. It can't be any worse!

5) Made a bottomless portafilter - Whole Latte Love sells OEM Gaggia portafilters. I got one and hit it with a hole saw in my garage followed up with my Dremel with a sanding wheel on it. Being reasonably careful I think it looks great. Anxious to try it out, again once things are up and running. I went this route hearing stories about bottomless PF's sold for Gaggias because they were 58mm, but not working because the way they attach to the group were incorrect. if they fit at all they tended to back themselves out. No thanks! I knew a modded OEM would fit and stay like an OEM.

Some general notes on this to save anyone else time:

- Classic OPV does fit fine- Old OPV needs a 1/8" pipe plug- Low pressure lines (3-way valve blow-off, Tee near pump for water supply, new OPV's blow-off) are all 1/4" barbed- High pressure lines (pump to boiler, steam valve) are 3/16" barbed- 3-way valve blow off line is a high temp handling tube as delivered from the factory (seems a bit unnecessary since water doesn't stay in it long but FYI)- The new OPV's inlet was a connection type I'm not familiar with and definitely didn't have on my original setup. However a simple 90 degree elbow with 1/8" NPT adapted it to what I needed to work with- McMaster-Carr is great for supplies. I got my gauge, tubing, and fittings there.- Brass pipe fittings are fairly cheap, most of these are rated for 1,000 psi or more and were $1 - $2 each.- My pressure gauge is nice and big and fat and bolts through the front of the lower part of the machine. but if I did it again I'd get a smaller gauge - having 1/8" pipe on it instead of 1/4 to adapt down would have saved on fittings and possible leak points, and I'd have bought a panel mount style that used a clip on the back vs. screws from the front - it would have been easier to install.- If you put a gauge in the bottom like I did, be mindful of the drain tube inside and place the gauge accordingly. You'll have plenty of room to clear the pump but here also be mindful of the direction your fittings point to get a clear shot for them.

I'm currently waiting on a length of high pressure tubing to connect the pump to the OPV and I'll be back in business. It should be here tomorrow or Wednesday. then it's time to set the OPV pressure and of course check for leaks and tighten fittings if necessary. The Baby Class came with a basket with a single small hole in it, I resume for pods, and I am planning on using it for my pressure tests. I'll seal up the hole and it'll be a blind basket I can also use for backflushing. No need to buy a new basket.

This is lacking pictures, I know. I'll have them up soon but wanted to get this started. It's long and mostly of interest only to Baby Class owners but if it helps I'm glad to return the favor.

Let us know how the copper preheat works. I saw minor temp stability improvement but ran into pressure issues. It seemed to almost get a vapor lock sometimes in the middle of the shot. The vibration noise also drove me nuts!

You will love the bottomless portafilter!

One other thing you may want to consider since she is opened up it to put an inexpensive thermocouple against the boiler under the copper tube so you have an idead of where in the heat cycle you are so you can surf the boiler easier.

Very nice tutorials there, given the name on them and your forum name here, they are yours? Nice work! I thought about taking pictures for brief instructions on the screw locations but it looks like there's no need as you have it well covered. I wish I'd seen these a week ago, would have made things easier.

I had most of the OPV figured out, when it comes down to it it's just plumbing. I like your idea of completely replacing the 11 bar piece with an elbow, that would have worked fine. I didn't want to mess with the factory high pressure connection there, so I left it. I considered replacing the factory plastic 3-way Tee with a 4-way tee, to allow me to leave the existing OPV and also plumb in the new one but didn't want the extra lines or chance that a pair of them would act "funny' together. There are a number of possibilities that would work. If I did it again I'd likely go your way, replacing it with an elbow would be a little cleaner and we're in that area anyhow. I didn't realize that teflon tube would reach, I figured it was too short and ditched it without trying. I was also skeptical of the pressure it could handle, though on looking it up it would have been fine.

I'd seen the Silvia wands in pictures, and at a glance the shape of it made it seem like it would work. I would like it if all wands from all companies could simply be 1/4" OD tubing but I found by measuring mine that wasn't the case. I could never get a clear answer on what diameter the Silvia wand was, only that it was "different". Also it seemed that the bare wands for sale in the $25 or so range were backordered, only the $75-ish kits were on hand. I watched for several weeks, and when I stumbled across this stainless "like for like" tip swap I went for it (and the video on their site must have convinced me it was a good alternative). I'm reasonably handy and own a Dremel, so once again had I seen your tutorial first I may have gone that direction. Assuming the wands ever got back into stock that is.

Interesting that you saw what may have been vapor lock. I know of that with cars, my old Jetta and a friend's Civic both had an issue with gas vaporizing in the fuel lines, they ran too near the exhaust and if you tried to start the car within say 10 - 20 minutes after last turning it off, it wouldn't start back up. You'd have to pop the hood and wait for it to cool, then you were OK to go. I can imagine that the heating elements on the side of the boiler might get hot enough to boil the water in the copper tubing. Argh, I'll have to watch for that. My aluminum foil seemed like a good idea, however it could be too much of a good thing. The machine is monitoring the boiler temp only, and what works for it could be too hot elsewhere. 200-ish deg F inside the boiler might lead to something over 212 deg F in a copper line outside of it.

I've been thinking about thermocouples to measure water temp but wasn't sure where to put them. If I do it, I'd like to hard wire it and leave it. In the center of the coffee grounds sounds perfect but is a bit unreasonable! I couldn't think of a place in that area that would keep things sealed. I considered buying a bolt with a thermocouple built inside of it, then drilling and tapping a new hole somewhere, but it seemed excessive. I may end up going with the PID heater control... I've seen threads (either here or Home-Barista?) that showed before & after measurements, and they showed a much more stable temperature. But I haven't measured it myself, not yet that is.

For what it's worth I love to tinker. I am often guilty of jumping into things like this and modding them because it sounds fun and seems like a good idea, and not based on actual experience. Sometimes I fix problems I don't even have. FYI in case it sounds like I know what I'm doing!

I've got some pics off of my phone now and will take more and post them up soon. My parts should arrive today or tomorrow and I'm anxious to get things back up and running.

Yeah, they are my tutorials. Sorry you didn't have them. I know one link is lurking around in an old thread but at least they are now in a thread that is easily searched. Also check out the gaggia yahoo group if you haven't - lots of good folks over there.

The teflon reaches, but the piece that came with the kit was tight. I ended up just ordering a length of Teflon and silicon for the return from mcmaster.

I am guessing your right about the vapor lock. It seems strange, but like you said the heating element may be hot enough to flash boil the water in the line. Usually it was a lack of flow starting the shot - if you stopped it and quick restarted it would flow fine. I just got annoyed and unwrapped the copper, but it might be worth getting a silicone trivet/potholder and cutting strips to go between the copper and the element. I never though of it at the time but that would probably easily fix the issue.

As far as the TC, I never got so advanced as to actually measure the water temp. Unless you are PID's will will have a decent intershot temp swing so I always though exact temps were sort of pointless. I sandwiched the TC to the middle of the outside of the boiler with a pipe clamp and a piece of silicone. It at least lets you know where you are in the thermostat swing range and makes it easier to surf. I think there was a thread here or HB under poor mans pid or something like that.

One thing to watch out for during your tinkering. There is a little plastic gasket on the back of the drip tray where the three way dumps. It is not attached firmly to the drip tray and in the course of my tinkering it fell off and must have fallen into the garbage pile. It's a $15 little stupid piece of plastic and if you dont have it, water splashes down the back of the tray and onto the counter. Don't accidentally throw it out! I thought I had a plumbing leak for a couple of weeks until I figured it out :)

Thinking about the copper tubing and the insulation - I'm picturing a scheme where there's insulation around the exterior of it, and perhaps additional insulation directly between the heating elements and the tubing as well. The idea would be that the boiler preheats the water, not the heating elements (not directly anyhow). I'll play with it as needed, if it's a problem. Glad you mentioned it, if things seem stuck I may not have though of vapor lock and instead figured I just had something plugged.

I'll play with temperatures perhaps by sticking a thermocouple up the portafilter spout and see what comes out. Perhaps use the "pod basket" with the single hole if it seems to flow well, not too fast or too slow. I dont' have much on hand right now except a cheap digital thermometer but I'll give that a try and look at thermocouples later.

Thanks for the mention of the gasket, I know exactly where it is having looked it up now on the parts diagram. I did pull the tray off for a while to make it easier to cut the hole for the gauge, i'll double check it's still there.

OK, on with some pictures. The pdf's linked are awesome and enough to know what the innards look like, but here are some more just for fun. These are part FYI an part to give an idea for others how to go about these mods. This is not complete as I dont' yet have the rest of the needed tubing.

Following is a picture of the inside of the lower unit, it's been pulled out and flipped upside down. You can easily spot the pump, and the "11 bar assembly" (static set OPV) is the black plastic piece ont he far right of it. The 3 way tee feeds the pump and has input from the water tank and the blow off of the OPV itself. The pink hose is the high pressure line feeding to the boiler.

Next is the boiler area itself, inside the upper unit. The same pink tube feeds into the bottom of the boiler, no OPV up here like the Classic's. The black box to the right is also attached to the boiler, it's the 3-way solenoid and the tube off the top of it is the blow off (heads toward the drip tray).

OPV disassembled. not much to it, it unscrews. There's a spring inside pushign on a diaphragm. Whent he pressure is high enough it's able to push the diaphragm into the spring and water blows by. You could lower the spring pressure (which would lower the setting of this) by partially unscrewing it, but you gamble on unscrewing it to the point where it blows the entire thing off when you make coffee. Could also try cutting a coil, but it's a guess as to where you'd end up. It would be very cheap to try and may get you close enough! Better to just replace it in my opinion.

Tubes are terminated and lines started. Of note is the pink high pressure hose coming up from the pump (lower right of picture) going into the tubing around the boiler. At the other end of the tube is a tee, to feed both the boiler and also a gauge. I placed the tee here originally planning to put the gauge on the side of the machine in the upper housing. I since changed it to the lower part, necessitating a longer line (which is what I'm waiting for now). I think this will end up beign a lot easier, I won't have to fish around to attach thigns with a cover halfway on, nor wonder about bent hoses, etc.

*** Note - do not run the lines to the OPV this way! These are backwards. High pressure feeds the left, the blow-off is on top. This picture does show them backwards! I caught it and fixed it. ***

I had to rearrange a few things to get the cover to fit on, having overestimated the available space between the front and lower units, the extra tubes I'd added tended to want to smash into each other. They flowed water but I wasn't happy with things being so tight. There's room in there though and it's been done, so the current setup while functionally the same is a little different than the pictures above. I have new pics but need to upload them.

I also had a small leak (dripped every 5-10 seconds) from the 11-bar OPV where I plugged it. I pulled the plug, stuck the original seal and half of the original spring (cut it) in there, then put my plug back in as well. So it should be double duty - the original seal + the spring fully coil bound to keep that seal in place, + my pipe plug with a thorough dose of pipe dope on it = no more leaking there. Jon I like your method even more in this area, yank the whole deal and put a 90 degree fitting in place instead.

The almost good news is that w/ that leak fixed, almost everything works. Almost. The pump pumps, the pressure gauge hits about 9.5-10 bars w/ the system closed, and I heat water, create steam, and everything else. No other leaks seen either. Almost joy - except there's no water coming out of the group head! Did a little researching, checking wiring diagrams, etc. and it's the 3-way solenoid, staying closed at all times and not allowing water to leave the boiler. Traced this down to one of the switches - when I pulled the top cover off at the start of this project I unplugged the wires from it, however one of them had a great grip on the spade terminal and yanked it out. I thought I got it back in correctly, seemed simple, but apparently not. When pulling the switch and investigating, it "unsproing" and sent little bits flying about the area and has not worked since (obviously)! I will attempt again to get it back together or may have to buy another. They don't look expensive but it's a dumb thing to have to deal with and completely my fault.

I've tracked down for certain (wiring diagram printed and multimeter in hand) that even after reassembly the switch isn't working correctly and is not making the correct connection to the solenoid (normally a solenoid opens when the pump is on, closes when the pump is off, and stays closed as it's "normal" position - mine just stays closed 100% of the time because it is not getting what it needs through the switch).

So I'm fixing or buying a switch, and then I should be able to say I've succeeded. I hope it's worth it in the end!

*** JON - I you read this (or any others), can you check something simple please? When the machine is on, the green power light (left) is on as well. There's a green light on the right that flips on and off with the boiler temperature. Above and below are for coffee pumping and steam. Can you or anyone let me know if those light up or stay dark when they are pressed? Mine stay dark, but it seems there's an LED in the switches themselves and so I should see them light?***

While the good switch may still be functional, if it's not completely up to snuff (should light but doesn't) I'll replace it too. I don't want to skimp at the last minute, and while I may in fact be a hack I don't want any aspect of the machine to not be working correctly.

(and as a side note we mentioned vapor lock, is there any chance your solenoid was acting up as well for some reason?)

Hi, I want to place a pressure gauge as well. I plan to get just a cheap 40mm pressure gauge on ebay with a 0-14 bar range. The issue I'm having is.. can I use an ordinary PVC pipe to attach the gauge to the machine? or do I need a copper tubing or just a braided reinforced pvc? and where will I attach it? Thanks!

Sorry for missing your question - I am about 99% sure that those lights go on when the switch is pressed. As for the vapor lock, the solenoid was working fine. It was usually mid shot and the flow would taper off. If I turned off the pump and then restarted it I would get flow back. No issue once I removed the copper with the same solenoid.

As far as the pressure gauge, not sure exactly how you would do it. You do want an oil filled gauge to dampen the vibe pump spikes though.

I'm a bit confused looking at the pictures. Where does the water from the pump enter the OPV in these photos? (it looks like the high pressure line is going into the top of the OPV and a low pressure line going into the side - which makes no sense to me - since the classic OPV bleeds the excess out the top back to the reservoir).OH ... nevermind ... I see your note that you figured this out.

Also ... where does the copper tubing preheater plumb into all this? I always figured that if you were going to wrap tubing around the boiler, you would need to use the OPV on the pump rather than the classic OPV on the boiler - so the OPV wouldn't be bleeding heated water off. But, again, this is probably just me not being able to make out from the pictures where you are routing the copper tubes.

I'm very curious ... so I'd love to see more pics of how you have things plumbed. The boiler sure looks new and shiny - I don't think I've ever seen such a shiny Gaggia boiler before.

Looking over your photos again ... I still think you are pumping your preheated water into the OPV which will then bleed off all that preheated water. I think this is a mistake and you would have been better off using the pump mounted OPV (though the Classic is a better performing OPV - or looks like it should be). I think you need to figure out how to get the OPV into the water line BEFORE the preheating coil so any water the OPV bleeds off is cool water -- otherwise you are wasting all that effort to preheat it.

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